1. Field of the Invention
The present invention relates to carriers, port apparatuses and facility interfaces, and more particularly to semiconductor wafer carriers, port apparatuses and facility interfaces.
2. Description of the Related Art
With advances in electronic products, semiconductor technology has been applied widely in manufacturing memories, central processing units (CPUs), liquid crystal displays (LCDs), light emitting diodes (LEDs), laser diodes and other devices or chip sets. In order to achieve high-integration and high-speed requirements, dimensions of semiconductor integrated circuits have been reduced and various materials, such as copper and ultra low-k dielectrics, have been proposed along with techniques for overcoming manufacturing obstacles associated with these materials and requirements.
FIG. 1A is a schematic drawing showing a traditional via hole structure. A copper layer 110 is formed over a substrate 100. An ultra low-k dielectric layer 120 is formed over the copper layer 110. A via hole 130 is formed within the ultra low-k dielectric layer 120 to expose the top surface of the copper layer 110. If the copper layer 110 is exposed to air, the top surface of the copper layer 110 reacts with oxygen in air, forming a copper oxide layer 140 due to oxidation. The situation becomes worse if moisture is also involved. The copper oxide layer 140 can adversely affect the electrical connection between the top surface of the copper layer 110 and a conductive via plug filled into the via hole 130. In addition, the ultra low-k dielectric layer 120 by itself absorbs moisture when exposed to air. Accordingly, great care should be taken to avoid exposure to air during critical process steps, such as via opening, formation of copper seed layers, copper chemical mechanical polish (CMP) and formation of the ultra low-k dielectric material.
Traditionally, after a critical process step, the substrate 100 is removed from the process chamber that performs the critical process step and temporarily stored in a FOUP until subsequent processing. When the door of the FOUP is removed to allow placement of the substrate 100 in the FOUP, air from the surrounding environment including oxygen, moisture and/or airborne molecular contamination (AMC), flows into the FOUP. After the door is closed, the air is sealed within the FOUP with the substrate 100. As described above, oxygen tends to react with the copper layer 110 formed over the substrate 100 to form the copper oxide layer 140.
In order to address this problem, a “Q-time” is required after a critical process step is performed in the semiconductor manufacturing process. The next process must be performed on the substrate within a set predetermined time period or Q-time, such as from 2 to 4 hours. If a subsequent process, such as formation of a barrier layer, does not occur within the time period, a cleaning process is required to remove any copper oxide layer 140 that may be formed over the copper layer 110.
Due to high integration of semiconductor devices over substrate 100, a semiconductor process usually has a plurality of the critical steps, each with an associated Q-time designed to protect the substrate. These Q-time requirements complicate the manufacturing processes. In addition, if a Q-time is missed, additional steps such as cleaning steps increase process time and complexity.
FIG. 1B is a schematic cross-sectional view of a prior art FOUP. The FOUP 150 protects wafers stored therein from being contaminated by particles within the environment having AMC around the FOUP 150. The AMC may be generated from facility pumping systems. The FOUP 150 includes an enclosure 160 and a door 170. The enclosure 160 includes a frame 165. The enclosure 160 also includes outlet check valve 173 and inlet check valve 175.
During removing the door 170 or open the enclosure 160, AMC diffuses into the enclosure 160. After the door 170 is transferred to seal the enclosure 160, AMC remains in the enclosure 160. In order to remove AMC in the enclosure 160, the inlet check valve 175 is disposed at the bottom of the enclosure 160 through which nitrogen is provided into the enclosure 160 to carry away AMC from the enclosure 160. Nitrogen provided within the enclosure 160 may push the door 170 away from the enclosure 160. The outlet check valve 173 is disposed at the bottom of the enclosure 160 through which AMC within the enclosure 160 can be removed.
When the door 170 is configured to seal the enclosure 160, the door 170 is transferred and contacts a gasket 180 so as to seal the enclosure 160 to prevent particles flowing into the enclosure 160. When the enclosure 160 is unsealed, the door 170 is unlocked and transferred directly away from the enclosure 160.
From the foregoing, it can be seen that improved cassettes or carriers and facility interfaces therefor are desired.